Characteristics of transparent conductive Al-doped ZnO and Ag–Ti tri-layer thin films prepared by multi-target magnetron sputtering

Al-doped ZnO (AZO) and Ag–Ti films were successfully deposited on glass substrates by multi-target magnetron sputtering to form the high transparent AZO/Ag–Ti/AZO multilayer. The optical, electrical properties and lifetime performance were investigated at various AZO and Ag–Ti thicknesses. As the AZO thickness was fixed at 10 nm and Ag–Ti thickness was varied between 6 and 22 nm, it can be found that AZO10 nm/Ag–Ti10 nm/AZO10 nm possessed good conductivity and highest transmittance in visible region. Then an AZO thickness adjustment of 10–90 nm was performed. With increasing AZO thickness from 10 to 70 nm, the transmittances of AZO10–70 nm/Ag–Ti10 nm/AZO10–70 nm films were all above 80% in the visible region and optimal transparency can be reached at AZO thickness of 70 nm. Although the conductivity in AZO/Ag–Ti/AZO films was decreased with increasing Ag–Ti thickness, the resistivity of 4.95 × 10− 4 Ω-cm in AZO70 nm/Ag–Ti10 nm/AZO70 nm was still acceptable. From the lifetime tests under normal circumstance, these multilayers almost showed the same transmittance and resistivity from 0 to 90 days. Furthermore, the AZO70 nm/Ag–Ti10 nm/AZO70 nm exhibits the highest figure of merit of 8.93 × 10− 3 Ω− 1, indicating that the multilayer has high potential in optoelectronic applications.